Did any of you see the August 2004 of one of the MOPAR magazine ?? They dynoed a Dodge truck with a 5.2 in it and added headers, intake, exhaust, and the superchips tuner. They dynoed the truck totally stock and then after each mod, they made a total of 35hp gain and 25 Torque. The Superchips alone gave like 20Hp alone IIRC. So if it can work on a 5.2, I am pretty sure the gains on a 5.9 would be just as much or greater !!!!